Delivering Passivhaus at scale – what have we learnt?

Passivhaus, the building standard focused on ultra-low energy buildings that require minimal heating or cooling, is most associated with small project, one-off ‘Grand Design’ type homes. But with the drive to deliver the lowest carbon buildings with the highest wellbeing standards, we are seeing the adoption of Passivhaus at a scale not yet  seen before in the UK market.   

The Passivhaus Standard has emerged as a leading framework for creating buildings that prioritise energy efficiency and occupant comfort. We have been at the forefront of this movement, delivering the largest certified Passivhaus buildings in the UK – Urbanest, Battersea at Palmerston Court – and applying Passivhaus principles elsewhere.   

For owner-occupiers, such as universities and research institutions, this relationship is particularly important as it enables reduced operational costs, improved occupant comfort, and long-term sustainability through reductions in carbon emissions. These all combine to make the investment worthwhile.   

What is Passivhaus  

The Passivhaus standard is a rigorous and highly efficient building methodology designed to create comfortable environments that require minimal energy input. Its success lies in achieving airtightness, eliminating thermal bridges, and incorporating high-performance insulation, energy-efficient glazing, and heat recovery ventilation systems. Ultimately, these buildings heat and cool themselves.  

One often overlooked factor is the balance between glazing and solid wall elements. Ideally, a Passivhaus building should have a one-third glass to two-thirds solid wall ratio to minimise energy loss while optimising natural light. Straying from this ratio may risk overheating in summer and heat loss in winter, undermining the building’s performance.  

Lessons learned and key considerations for Passivhaus success  

Delivering Passivhaus at scale requires contractors to adopt a meticulous approach to design, construction, and quality control. High-quality execution is critical for achieving sustainability goals and ensuring that all components meet the stringent requirements of the Passivhaus standards.   

1. Training and workforce development 

Passivhaus projects rely on skilled workers who understand the complexity of airtightness, thermal performance, and renewable energy systems. Labour shortages and skills gaps remain a challenge, but investing in workforce training can bridge this divide. At Begbroke Science Park, where Passivhaus principles were applied to laboratory spaces, specialist consultants were brought in to upskill teams on mechanical ventilation systems and airtight construction techniques. This collaborative approach between contractors, consultants, and suppliers ensured that all parties understood the demands of Passivhaus and could deliver to the required standard. 

Upskilling does not stop at construction teams. Workshops with architects and designers early in the process help align design intent with constructability. This is particularly important for avoiding pitfalls, such as overly complex designs or unsuitable materials, which can undermine a project’s ability to achieve Passivhaus certification.  

2. Material procurement and supply chain management

Material procurement and supply chain management play a vital role in the success of Passivhaus projects. Developing strong relationships with suppliers experienced in providing Passivhaus-compliant materials ensures consistent quality and reduces delays.  

At Palmerston Court, terracotta façades were selected not only for their aesthetic appeal but also for their durability. These materials were tested off-site before installation to ensure they met the stringent standards required for Passivhaus certification. The facade system (not just the tiles) was tested off and on site. 

3. Workmanship, quality control and progressive testing

Achieving Passivhaus standards demands exceptional workmanship and progressive quality control.  

At Palmerston Court in Battersea — where student accommodation designed by AHMM for Urbanest was, at the time of completion, the largest Passivhaus building in the UK and the eighth largest globally — this approach was critical. 

Some of the key factors for success on the project when it came to QA included: 

• The use of BIM to track and manage the QA process   

• Close collaboration with our Passivhaus Consultants and the Passivhaus Institute   

• Educating our team and the workforce on the stands required and ensuring they were part of the process  

• We carefully tracked all the elements of work that could impact our Passivhaus performance to ensure we inspected and collected the right information  

• We procured a temporary sealing contractor to ensure all testing was carried out effectively  

• Carried out onsite benchmark testing of critical components and interfaces to de-risk the final building test  

• Caried out sectional testing of floors with a focus on top and lower levels where the majority of the interfaces were   

• When we experienced leakage we rectified this and re-tested where required   
• We carefully considered the final testing strategy and planned this meticulously to ensure a successful final test   

4. Efficient ventilation systems  

The implementation of efficient mechanical, electrical, and plumbing (MEP) systems is also critical. Centralised ventilation systems with heat recovery and efficient heating and cooling systems, such as ground-source or air-source heat pumps, are essential for reducing energy consumption. Moreover, passive design techniques – such as incorporating shading measures and optimising building orientation – are vital for minimising energy use and preventing overheating. 

At Begbroke Science Park for the University of Oxford, we applied Passivhaus principles to create high-performance laboratory spaces as part of a £59 million development. By integrating mechanical ventilation with heat recovery, we significantly improved indoor air quality – crucial for laboratory environments – while conserving energy. The project achieved an airtightness score of 1.2 m³/hr/m², demonstrating the value of rigorous quality control and sustainable design. 

5. Prioritising design simplicity

For universities and other owner-occupiers considering Passivhaus-standard buildings, it is essential to prioritise the fundamentals of design. The initial design concept must integrate Passivhaus principles from the outset, including appropriate building form, orientation, glazing ratios, and entrance strategies. This foundational work is critical for ensuring operational performance over decades. 

In addition, simplicity in design should be embraced. Every added complexity introduces potential failure points, and the most successful projects typically feature clean, straightforward designs. This not only maximises performance but also enhances maintainability throughout the building's lifecycle.  

The business case for Passivhaus 

While achieving Passivhaus certification can add approximately 4-9% to initial capital costs, the long-term financial and environmental benefits more than justify the investment. For owner-occupiers, such as universities and research institutions, Passivhaus offers a proven methodology for delivering buildings that are operationally efficient, environmentally sustainable, and future-proofed. The benefits include reduced operational costs, enhanced occupant comfort, and long-term value through durable materials and systems. Passivhaus buildings typically consume 75-90% less energy than conventional buildings1, significantly reducing operational costs over their lifespan, while also providing flexibility for future retrofitting or repurposing. 

Buildings that benefit  

Delivering Passivhaus at scale requires contractors to adopt a meticulous, collaborative approach, focusing on quality, training, and sustainability. Lessons learned from projects such as Palmerston Court and Begbroke Science Park demonstrate that with the right expertise and attention to detail, Passivhaus principles can be successfully applied to large-scale developments.  

For owner-occupiers, the long-term benefits of Passivhaus – reduced operational costs, enhanced occupant comfort, and lower carbon emissions – make it a compelling investment in the future of sustainable construction. By embracing these principles, we can create buildings that benefit both users and the planet for decades to come.